A204894 Least prime p such that n divides p-q for some prime q<p.

3, 5, 5, 7, 7, 11, 17, 11, 11, 13, 13, 17, 29, 17, 17, 19, 19, 23, 41, 23, 23, 29, 53, 29, 53, 29, 29, 31, 31, 37, 67, 37, 71, 37, 37, 41, 79, 41, 41, 43, 43, 47, 89, 47, 47, 53, 97, 53, 101, 53, 53, 59, 109, 59, 113, 59, 59, 61, 61, 67, 127, 67, 131, 67, 67, 71

Offset

1,1

Comments

For a guide to related sequences, see A204892.

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Formula

n + 2 <= a(n) <= prime(n+1). - Charles R Greathouse IV, Jul 17 2015

Mathematica

(See the program at A204892.)

Prog

(PARI) a(n)=forprime(p=n+2, , forstep(k=p%n, p-1, n, if(isprime(k), return(p)))) \\ Charles R Greathouse IV, Mar 20 2013
(PARI) a(n)=if(isprime(n+2), return(n+2)); my(s=if(n%2, 2*n, n), t); forprime(p=s+3, , t=p%n; forstep(q=if(t%2, t, t+n), p-s, s, if(isprime(q), return(p)))) \\ Charles R Greathouse IV, Jul 17 2015

Crossrefs

Cf. A204892, A204903, A000040.

Sequence in context: A302756 A305216 A087821 * A109258 A088081 A206768

Adjacent sequences: A204891 A204892 A204893 * A204895 A204896 A204897

Keyword

nonn

Author

Clark Kimberling, Jan 20 2012

Status

approved